Internal dividing walls in many buildings are commonly constructed from vertical studs or construction members supporting wallboards on either side. It is also usual to provide wiring within the wall, passing through the studs. This construction technique gives rise to safety problems, since it has been found that the cables passing through the studs at a depth close to the attached wallboard can be exposed to accidental penetration by nails, screws or other fasteners driven in through the wallboard into the studs, for mounting the wallboards or otherwise. This has given rise to the development of metal protector plates, ,applied to the stud face, on either side of the opening through which wiring or piping passes. These metal protector plates have proved effective in preventing the insertion of nails, screws etc. into the studs, and hence preventing them penetrating any wiring or piping.
Previously, the problem was most severe with wooden studs. Protector plates have been developed for use with wooden studs. Such plates were often configured from sheets of metal with nail-like prongs extending therefrom, as disclosed in U.S. Pat. No. 3,240,869.
More recently, the assignee of the present invention has developed a construction stud protector plate, disclosed in published Canadian Patent Application 2,097,969, for use with steel studs. This discloses a metal protector plate, configured for easy and safe attachment to steel studs.
Generally, this provides a metal protector plate adapted to be positioned at the front or back face of a steel stud. At one side, the protector plate has a short side plate, while on the other side it has two bendable tabs. It is intended for the bendable tabs to be bent around a side of the steel stud, while simultaneously forming depressions or deformations to securely retain the protector plate in position. To facilitate this, protuberances are provided, for engagement by a pair of pliers.
Such a construction adequately protects the cabling and prevents penetration by nails, screws etc. However, it has numerous disadvantages. The overall design of the steel plate is relatively complex, for the function it has to serve. Attachment of the plate requires a number of separate operations, namely location on the stud, and two separate bending operations to bend the tabs. Fastening of the steel plate results in deformation of the steel stud. More importantly, each protector plate only protects one side of the stud, so that it is necessary to fasten two separate protector plates, wherever cabling etc. passes through a stud.
Also, it provides no protection to the opening in the stud or beam.
The Canadian Electrical Code now calls for the application of protector plates to all studs, including metal studs, that have electrical cables passing therethrough at a distance less than 11/4 inches from a stud face.
The Canadian Electric Code also specifies that a bushing must be inserted in the hole or opening of the steel stud, where non-metallic sheath cable is to be passed therethrough. Such a bushing is intended to have two purposes, namely to prevent damage to the cable when it is pulled through the stud opening which may have sharp edges, and also to prevent any shape edges cutting into the cable once installed, due to vibration in use.
In any installation, there may be requirements for a cable to pass through numerous studs, requiring a large number of protector plates and protective bushings to be installed. With known devices, for each stud, a separate bushing and two protector plates must be installed.
It is therefore desirable to provide a protector plate design which is capable of quick and easy insertion. Preferably, such a protector plate design provides a protector plate unit which will simultaneously protect both faces of the stud, and provides a bushing for the opening in the stud. More preferably, it should be capable of secure attachment, without requiring any separate deformation or attachment operation.